/* * Ogg bitstream support * Mark Hills <mark@pogo.org.uk> * * Uses libogg, but requires libvorbisenc to construct correct headers * when containing Vorbis stream -- currently the only format supported */#include <stdio.h>#include <ogg/ogg.h>#include "avformat.h"#undef NDEBUG#include <assert.h>#define DECODER_BUFFER_SIZE 4096typedef struct OggContext {    /* output */    ogg_stream_state os ;    int header_handled ;    ogg_packet op;    /* input */    ogg_sync_state oy ;} OggContext ;#ifdef CONFIG_ENCODERSstatic int ogg_write_header(AVFormatContext *avfcontext) {    OggContext *context = avfcontext->priv_data;    ogg_packet *op= &context->op;        int n, i;    av_set_pts_info(avfcontext, 60, 1, AV_TIME_BASE);    ogg_stream_init(&context->os, 31415);        for(n = 0 ; n < avfcontext->nb_streams ; n++) {        AVCodecContext *codec = &avfcontext->streams[n]->codec;        uint8_t *p= codec->extradata;                for(i=0; i < codec->extradata_size; i+= op->bytes){            op->bytes = p[i++]<<8;            op->bytes+= p[i++];            op->packet= &p[i];            op->b_o_s= op->packetno==0;            ogg_stream_packetin(&context->os, op);            op->packetno++; //FIXME multiple streams        }	context->header_handled = 0 ;    }        return 0 ;}static int ogg_write_packet(AVFormatContext *avfcontext,			    int stream_index,			    const uint8_t *buf, int size, int64_t pts){    OggContext *context = avfcontext->priv_data ;    AVCodecContext *avctx= &avfcontext->streams[stream_index]->codec;    ogg_packet *op= &context->op;    ogg_page og ;    pts= av_rescale(pts, avctx->sample_rate, AV_TIME_BASE);//    av_log(avfcontext, AV_LOG_DEBUG, "M%d\n", size);    /* flush header packets so audio starts on a new page */    if(!context->header_handled) {	while(ogg_stream_flush(&context->os, &og)) {	    put_buffer(&avfcontext->pb, og.header, og.header_len) ;	    put_buffer(&avfcontext->pb, og.body, og.body_len) ;	    put_flush_packet(&avfcontext->pb);	}	context->header_handled = 1 ;    }    op->packet = (uint8_t*) buf;    op->bytes  = size;    op->b_o_s  = op->packetno == 0;    op->granulepos= pts;    /* correct the fields in the packet -- essential for streaming */                                                            ogg_stream_packetin(&context->os, op);                                                                          while(ogg_stream_pageout(&context->os, &og)) {        put_buffer(&avfcontext->pb, og.header, og.header_len);	put_buffer(&avfcontext->pb, og.body, og.body_len);     	put_flush_packet(&avfcontext->pb);    }                                                       op->packetno++;    return 0;}static int ogg_write_trailer(AVFormatContext *avfcontext) {    OggContext *context = avfcontext->priv_data ;    ogg_page og ;    while(ogg_stream_flush(&context->os, &og)) {	put_buffer(&avfcontext->pb, og.header, og.header_len) ;	put_buffer(&avfcontext->pb, og.body, og.body_len) ;	put_flush_packet(&avfcontext->pb);    }    ogg_stream_clear(&context->os) ;    return 0 ;}static AVOutputFormat ogg_oformat = {    "ogg",    "Ogg Vorbis",    "audio/x-vorbis",    "ogg",    sizeof(OggContext),    CODEC_ID_VORBIS,    0,    ogg_write_header,    ogg_write_packet,    ogg_write_trailer,} ;#endif //CONFIG_ENCODERSstatic int next_packet(AVFormatContext *avfcontext, ogg_packet *op) {    OggContext *context = avfcontext->priv_data ;    ogg_page og ;    char *buf ;    while(ogg_stream_packetout(&context->os, op) != 1) {	/* while no pages are available, read in more data to the sync */	while(ogg_sync_pageout(&context->oy, &og) != 1) {	    buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ;	    if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0)		return 1 ;	    ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ; 	}			/* got a page. Feed it into the stream and get the packet */	if(ogg_stream_pagein(&context->os, &og) != 0)	    return 1 ;    }    return 0 ;}static int ogg_read_header(AVFormatContext *avfcontext, AVFormatParameters *ap){    OggContext *context = avfcontext->priv_data;    ogg_packet op ;        char *buf ;    ogg_page og ;    AVStream *ast ;    AVCodecContext *codec;    uint8_t *p;    int i;         avfcontext->ctx_flags |= AVFMTCTX_NOHEADER;         ogg_sync_init(&context->oy) ;    buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ;    if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0)	return -EIO ;        ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ;       ogg_sync_pageout(&context->oy, &og) ;    ogg_stream_init(&context->os, ogg_page_serialno(&og)) ;    ogg_stream_pagein(&context->os, &og) ;        /* currently only one vorbis stream supported */    ast = av_new_stream(avfcontext, 0) ;    if(!ast)	return AVERROR_NOMEM ;    codec= &ast->codec;    codec->codec_type = CODEC_TYPE_AUDIO;    codec->codec_id = CODEC_ID_VORBIS;    for(i=0; i<3; i++){        if(next_packet(avfcontext, &op)){            return -1;        }        codec->extradata_size+= 2 + op.bytes;        codec->extradata= av_realloc(codec->extradata, codec->extradata_size);        p= codec->extradata + codec->extradata_size - 2 - op.bytes;        *(p++)= op.bytes>>8;        *(p++)= op.bytes&0xFF;        memcpy(p, op.packet, op.bytes);    }    return 0 ;}static int ogg_read_packet(AVFormatContext *avfcontext, AVPacket *pkt) {    ogg_packet op ;    if(next_packet(avfcontext, &op)) 	return -EIO ;    if(av_new_packet(pkt, op.bytes) < 0)	return -EIO ;    pkt->stream_index = 0 ;    memcpy(pkt->data, op.packet, op.bytes);    return op.bytes;}static int ogg_read_close(AVFormatContext *avfcontext) {    OggContext *context = avfcontext->priv_data ;    ogg_stream_clear(&context->os) ;    ogg_sync_clear(&context->oy) ;    av_freep(&avfcontext->streams[0]->codec.extradata);    return 0 ;}static AVInputFormat ogg_iformat = {    "ogg",    "Ogg Vorbis",    sizeof(OggContext),    NULL,    ogg_read_header,    ogg_read_packet,    ogg_read_close,    .extensions = "ogg",} ;int ogg_init(void) {#ifdef CONFIG_ENCODERS    av_register_output_format(&ogg_oformat) ;#endif    av_register_input_format(&ogg_iformat);    return 0 ;}